How to Calculate Window Tint Visible Light Transmission (VLT)

Window tinting films are measured in visible light transmission levels (or VLT). This means that when we discuss a particular film, be it for fitting to a car or any other application, we normally refer to it with it’s VLT value. VLT is measured in percentage ( % ), so if you hear about a tint product being referred to as a percentage, it is the VLT that defines that percentage value.

For example, a tinting film referred to as Charcoal 5% is a charcoal coloured tint with a VLT of 5% and likewise a film referred to as green 50% is a green coloured tint film with a VLT of 50%. But what does the number actually mean?

Well, in simple terms the VLT value is the percentage of visible light that will be allowed to travel through the window tinting film from the exterior face side of the film to the interior side. This means that a 5% film will only allow 5% light travel through and a 70% film will allow 70% light to travel. In effect, this means that lower VLT films will appear darker. For instance, it is normally 5% tints that we will see on limousines for privacy.

So, fitting a 5% tint to a window will allow 5% light to travel through the glass from outside to inside, right? NO! Because we need to take into consideration the actual VLT of the window before the tint is even installed. There is no such thing as a piece of glass, no matter how clear it appears, with a VLT of 100%. This is because glass naturally filters out a little bit of visible light.

Lets look at car window tinting as this is one area where we speak of VLT often due to the fact that many countries have laws in place limiting how dark car windows should be tinted. Most modern cars come from factory with windows reading a VLT somewhere between 72% and 78%, depending on manufacturer, model and country. Say, our example car’s windows read at 72% and we add a 50% window tinting film, what is the new and final VLT of our car’s windows after installation?

The sum is very simple: V1 x V2 = V3 (Where V1 is the original VLT of the glass before tinting, V2 is the VLT of the window tinting film and V3 is the final VLT value of the glass with tint film applied).

Our car’s windows original VLT = 72% and the tint = 50 %, thus V1 = 72 and V2 = 50

The sum is 72 x 0.50 giving us 36, which we will express as a percentage. So a window with an original VLT of 72% will then have a VLT of 36% after application of a 50% film.

Homework Organization For Students (And Their Parents)

I spend a lot of time at my seminars and workshops, on the phone and via email discussing the subject of homework organization. Actually, I spend a lot of time listening to parents complain that their children’s homework disorganization is driving everybody crazy!

Many students have such a hard time getting it together that by the time they finally sit down to do their homework, they are exhausted. No wonder they don’t want to do it! Getting organized will help alleviate exhaustion, bad attitudes, procrastination and rebelliousness.

Homework organization just makes life easier for everyone.

These are the homework organization tips that I use as a student, teacher and parent. Print this list and read it with your children. Then, post it on the fridge and refer to it often so that everybody (parents, kids, babysitters, grandparents) will be on the same organized page.

At School:

  • Write down every, single homework assignment in one place. I strongly recommend using a bound or wire notebook- definitely NOT a loose leaf binder. I don’t care how careful you are, pages will fall out, and then what? You won’t know what to do nor when to do it! A plain notebook is fine, but a datebook or calendar is the best. Some schools even provide these to students. Use it.
  • Write down homework assignments as you get them. This is mostly for older students that change classes and teachers, but it is a good habit for everyone. If the teacher says, “Oh, tonight I want you to read Chapter 4,” write that down in your notebook.
  • Write down every, single due date for a project or paper- even if you have a handout or syllabus. Handouts disappear (I think they hang out with loose socks), but you will still know what to do and when to do it if you have everything written down in your homework notebook.
  • Keep ALL of the day’s homework assignments together in one place. Don’t have a special place or page for math, another for writing, etc. You want to see everything in one spot.
  • Check your homework notebook Three (3) Times A Day: Before you leave school (or each class), double check to make certain that you have everything (books, paper, materials, etc.) that you will need later.

At Home:

  • Before you start doing your homework, look at your notebook and make sure that you are doing the right assignment, the right page, etc.
  • Before you put everything away, take one more quick look. Did you do everything? Good!
  • Make a decision about where you will put your completed homework: into a binder pocket, a special homework folder, etc. You may decide to have a color-coded folder for each class. If you choose to use folders, I strongly recommend using 3-hole punched folders and keeping them together in a 3-ring binder. Whatever you choose, stick to it! Don’t put your homework in your a binder today, a folder tomorrow… And, never, ever fold your homework into a book or throw it loose into your backpack! Shudder!
  • Use your Magic Homework Box. You do have one, don’t you? The Magic Homework Box is a box with all of the homework supplies and materials a student needs on a regular basis. These supplies only come out of the Magic Homework Box during homework time, so you always have what you need. Now, that’s magic!
  • Clean up as soon as you are finished with your homework. Now, not later! Put completed pages in your homework folder, then put the folder and homework notebook in your backpack. Not only will mornings will be less crazy, you won’t have to sit in class knowing that you did your homework and forgot it at home (doh!). Don’t forget to put away the dictionary and any other books you may have used.
  • Remember to put everything back into your Magic Homework Box. In my house, homework is not “done” until everything is cleaned up and put away.
  • Keep your backpack organized. Throw away all of those candy wrappers and random pieces of paper. Keep one area or pocket filled with a few items (pencils, a sharpener, maybe a calculator) so that you can do your homework anywhere- maybe even before you get home! Remove any graded test, project, report or paper that your teacher has taken the time to return to you. Why? You might need it to study for a test, for a portfolio or for a project. You can throw everything away at the end of the semester or the school year, but until then put each item in its own subject file, but NOT in the homework folder. Remember, homework folders are ONLY for completed homework that is ready to be turned in!
  • Don’t give up! They say it takes 21 days to form a good habit. If you forget to do something on this list, don’t stop trying. Hey, maybe if you remember to write down all of your homework or clean up for 21 days in a row, your mom or dad will do something extra nice for you! (Parents, that was a hint!)

A Note to Parents about Homework Organization

Please remember that your job is to give your children organizational tools and show them how to use them. Your job is NOT to organize your child’s homework! So, in the beginning, you might check your son’s homework notebook to make sure that he is writing down all of his assignments in one place, but you would never dream of calling the teacher and checking. You might watch as your daughter copies the science project due dates into her homework notebook; you will not do it for her.

Yes, I know that it is hard to let go- I’ve been there! But, we want our children to be organized and independent learners, right?

You can do it!

(For more information about recommended homework organization products and The Magic Homework Box, please see site information below.)

What is Bluetooth?

Bluetooth technology specifies a two-way, short-range radio link that enables communication between PCs, mobile phones, PDAs, and other computing, electronic, and home theatre equipment. With Bluetooth, you can easily synchronize contact or calendar data between a PDA and laptop, talk on a hands-free phone, or print without cables. It is a cable replacement technology like infrared, but offers many advantages over infrared.

The Bluetooth specification focuses on keeping costs low, power consumption minimal, and the size small. Its low power consumption means it can be used in battery-powered devices. Bluetooth offers faster data rates and greater   transmission  distances compared with infrared and there are no line-of-site restrictions. It operates at the 2.4 GHz radio frequency, ensuring worldwide operability.

History

Bluetooth is named after a 10th century Danish king, Harald Blatand (Harld Bluetooth) who was known for uniting warring groups in current-day Norway, Sweden, and Denmark. It was originally developed by Ericsson, but is now managed by the Bluetooth Special Interest Group (SIG).

The Bluetooth SIG is an industry group with members from the telecommunications, computing, and chip manufacturing industries. To date over 2000 companies are members. The Bluetooth SIG oversees a qualification program to ensure compliance with the standard and interoperability with other Bluetooth devices. Any device bearing the Bluetooth logo has successfully completed interoperability testing.

Technical Details

Speed: The gross data rate supported by Bluetooth is 1 Mbps. Actual data rates are 432 kbps for full-duplex and 721 kbps for asymmetric  transmission .

Frequency: Bluetooth uses the unlicensed ISM (Industrial, Scientific, and Medical) band at 2.4 GHz. In most countries, this band is available. In a few countries it is reserved for military use, but even these countries are moving to make the band available for general use. Because Bluetooth shares the same frequency range as 802.11b WLAN products, these two technologies cannot operate in the same space under some conditions.

Security: Bluetooth is designed to be as secure as wire using authentication and 128-bit encryption. Applications can also build their own security on top of the Bluetooth connection.

 Transmission  distance: Bluetooth’s typical range is up to 10m. The range depends on the radio power class used. A class 2 radio has a typical range of 10m. More powerful classes support longer ranges and have higher output powers. Most devices use a class 2 radio and mobile devices, like mobile phones, where low power consumption is crucial, can only use a class 2 radio.

Architecture: With Bluetooth, up to 8 devices can be connected simultaneously. A piconet is the term for a collection of Bluetooth devices connected in an ad hoc fashion. All devices are peer units, but one device acts as a master and the other slaves for the duration of the piconet connection. Each piconet can support up to 3 full-duplex voice devices. Within a 10m area, there can be up to 10 piconets.

Applications

Bluetooth is becoming the preferred wireless technology in the WPAN (Wireless Personal Area Network). Personal applications include:

– Users can connect PCs to transfer files.

– Workers can collaborate on the same document using Microsoft NetMeeting.

– Users can connect to a printer without cables.

– Users can synchronize data between a handheld PDA and laptop.

– Users can listen to music via a wireless headset.

– Users can talk on their mobile phone with a wireless headset.

– Users can connect their laptops to the internet using their mobile phone’s GPRS or UMTS network.

Protect Yourself From Sexually Transmitted Diseases: Promote Safe Sex

Sexually active persons are often victims of sexually transmitted diseases. While most people consider sex as a need, it is also a must that you should know all that you could about certain consequences of engaging in sexual activities especially when you change partners often. That is why be careful when choosing your sexual partner and make sure to maintain a clean personal hygiene. Sexually transmitted diseases are often caused by bacterial infection. While most kinds of these diseases are curable, HIV in particular is deadly. So if you want to enjoy a longer life span while enjoying the good things life has to offer keep yourself in check at all times by doing STD tests.

Sexually transmitted disease tests are often conducted in clinics with the help of a medical expert. However, for most people who find it inconvenient by setting an appointment for a test, a STD test can be conducted at home with STD test kits. These test kits can be purchased online and delivered straight to your doorsteps. This is truly a convenient method of keeping yourself in check since these cases are highly sensitive.

Even if you choose to get tested at a clinic, your results are still kept confidential. STD test kits have easily understandable instructions with it that can be easily followed to determine the result. Once you see a positive result, do not panic. Bear in mind that it is better to have found it an earlier stage to determine the best and fast way to cure your infection.

There are different kinds of sexually transmitted diseases. There are those which can only be spread through pure sexual contact either by oral, anal, or vaginal sex. There are also kinds which can be transmitted without sexual contact. The best way to prevent yourself from getting infected is of course by abstinence, avoiding sex. While most people cannot do this method, the use of condom is the second best method.

Although this is not full proof, with proper use, you can still enjoy the benefits of sex and peace of mind that you are safe from getting infected at least. Knowing more about STDs and promoting safe sex can help reduce the case of sexually transmitted diseases especially on young people who are sexually active.

If you happen to change partners often, keep your body in check at all times. If you happen to experience slight changes be sensitive enough to care and conduct STD tests at the convenience of your own home. Most of these sexually transmitted diseases do not show symptoms at the early stage and when left untreated can cause complications which can never be cured even on a long term basis. As long as it is not HIV, there is a sure way to rid yourself of bacteria that cause such infections. Always maintain proper and good hygiene especially on sensitive body parts.

Buying a Pressure Washer – Understanding the Lingo

If you have considered buying a pressure washer and have done a little looking, you are probably a little confused at the many choices and various terminology being used. It is important to know what the various acronyms mean and what whether or not a unit will meet your specific needs. The following article will help you understand what the main functions are of a pressure washer as they relate to specific cleaning jobs you need to do. It will also explain the common acronyms that are used and what it means to your purchase. If there is one thing you take from this information it should be this, do not skimp on quality. A pressure washer is a hard working machine that needs to be able to take years of abuse. It also performs functions that require quality craftsmanship. Pumping water under extream pressure is not something to take lightly. So be sure you purchase a quality unit such as a Karcher Pressure washer or Excel pressure washer. Spend the extra 10-20% over a bargin brand and you will save your self lots of frustration.

Whether or not you have chosen a particular brand, you need to think about the type of work you will be doing with the unit. This will help you determine what class of pressure washer you will need to buy. This is very important. You don’t want to spend more money than necessary on a unit that is much bigger than you need but on the other hand you don’t want to get a machine that takes for ever to complete the type of work you need to complete. If you are looking to accomplish small simple tasks like washing vehicles, cleaning small decks or patios then you should consider a light weight unit. If you have a fairly large driveway to clean every couple of months, a big deck or want to clean your house regularly, you should consider moving up to a medium sized machine. For regular use on large jobs such as big decks, lots of concrete and large house cleaning jobs then a large unit is in order.

I will attempt to classify the difference between large medium and small units as they relate to the types of jobs we mentioned but first lets discuss the features of a pressure washer and what they mean to you. The first thing to consider when evaluating what size unit you need is the PSI rating. PSI stands for ‘pounds per square inch’. This refers to the pressure that the unit can create which will directly affect the force behind the stream of water. The higher the PSI of the unit the more powerful the stream of water will be. Cleaning greasy construction equipment and cleaning grime off of concrete require more PSI to get the job done. Cleaning wood such as a deck would require less PSI due to the damage it can cause to relatively soft wood. The second feature of a pressure washer we will consider is the GPM. GPM refers to ‘gallons per minute’. This is the volume of water that the unit can constantly supply. For most projects the more water that comes through the nozzle the faster you can complete the job. So whether it is a driveway job that requires high pressure or a house wash which requires low pressure a high volume of water will get both jobs done quicker.

So classifying a unit as small, medium or large basically relates to the level of pressure and volume you can get with a specific machine. A small unit would normally be an electric or gas model with a pressure rating of under 1500 PSI. You could expect a GPM rating of around 1.5 GPM. This would be useful for automobile cleaning, removing dirt from patio furniture/outdoor fixtures and light house or deck cleaning. Electric units usually are not made for frequent use. So if you want to wash your car every week or so and clean the patio once a month this is a good choice. A medium unit is one that has 1500-2500 PSI and a GPM rating around 2-3. This would be good for a homeowner that wants to clean the driveway, wash the 2 story house and take care of the big deck. It can take lots of abuse and is made to be used more frequently. Finally for those you want to be able to handle any job that might come up and get it done as quickly as possible there is the ‘large’ category. This would be for units with PSI of 3000-5000 PSI. GPM ratings would be from 4 to 8 GPM. These would also be considered as units for commercial use as well. A large unit can clean a large area of concrete quickly and drive accessories like flat surface cleaners effectively. The high GPM ratings will help move dirt and strip stain from wood much quicker than lower GPM ratings. Keep in mind that your budget will come into play when considering the higher end units. Going from 2.5 GPM to 4 GPM can be a jump of 1-2 thousand dollars.

Another item to keep in mind is whether you need a direct drive or belt drive unit. The water pump is the core of your pressure washer. The drive system is what runs the pump system. A direct drive system is the typical configuration. It is a little cheaper but runs your unit at a higher RPM. This can put more stress on your machine and ultimately result in a lower life span. A belt drive system runs at lower RPMs and will create less wear on the machine. You can expect to pay about 20% more for a belt drive system and is only available on the larger units. If you plan on using your pressure washer several times a month throughout the course of a year, it would be a good idea to purchase the belt drive system.